Sumitomo Chemical Company, Limited

Hironobu Iyama

Naoki Inui

Hideo Nagasaki

Kyoko Tsuta

Manji Sasaki

Mutsuko Higo

Kunihito Miyake

Kanako Fukuda

Sadanobu Iwase

Kazuaki Yamamoto

Takeshi Kondo

To provide a liquid crystal polyester composition which is suited for use as a material for forming a liquid crystal polyester film having excellent thermal conductivity. Also, an excellent electronic circuit board is provided by using an insulating film obtained from the liquid crystal polyester composition. The liquid crystal polyester composition of the present invention is composed of a liquid crystal polyester, a solvent and a thermally conductive filler. The thermally conductive filler is contained in the amount of 50 to 90 volume % based on the total amount of the liquid crystal polyester and the thermally conductive filler, and the thermally conductive filler contains 0 to 20 volume % of a first thermally conductive filler having a volume average particle diameter of 0.1 &#x3bc;m or more and less than 1.0 &#x3bc;m, 5 to 40 volume % of a second thermally conductive filler having a volume average particle diameter of 1.0 &#x3bc;m or more and less than 5.0 &#x3bc;m and 40 to 90 volume % of a third thermally conductive filler having a volume average particle diameter of 5.0 &#x3bc;m or more and 30.0 &#x3bc;m or less.

Liquid crystal polyester composition and electronic circuit board using the same

An object of the present invention is to provide a light diffuser plate () which can illuminate the front side more brightly when incorporated in a surface light source () constituting a transmissive image display (). The light diffuser plate of the present invention comprises a transparent resin and a light diffuser dispersed in the transparent resin, wherein the transparent resin is a transparent resin which has a light transmittance [T] at a wavelength of 600 nm of 85% or more measured with respect to a thickness of a 2 mm thick plate-shaped specimen, and a ratio [T/T] of a light transmittance [T] at a wavelength of 365 nm to the light transmittance [T] is 0.90 to 0.99. The transparent resin is polystyrene or the like, an average particle diameter of the light diffuser is from 0.5 to 5 &#x3bc;m, an absolute value [|&#x394;n|] of a difference in a refractive index between the light diffuser and the transparent resin is 0.05 or more, an amount of the light diffuser is from 0.1 to 10 parts by mass based on 100 parts by mass of the transparent resin, and the light diffuser plate has a thickness within a range of from 1 to 5 mm.

Light diffuser plate

Polybutadiene composition

There is provided a co-condensation product obtainable by subjecting a p-alkylphenol to reaction with formaldehyde in the presence of an alkali catalyst to prepare a resol type condensate, and subjecting the resulting resol type condensate to reaction with a m-substituted phenol such as resorcin in the presence of an acid catalyst, wherein the content of the m-substituted phenol is not higher than 4% by weight, and the content of a component having a molecular weight not higher than 1,000 excluding both the p-alkylphenol and the m-substituted phenolis at least 25% by weight based on the total weight of the co-condensation product. This co-condensation product is low in fuming and in hygroscopic properties, exhibits excellent adhesiveness in vulcanizing adhesion between rubber and a reinforcing material, and further provides a vulcanized rubber article of high hardness.

Co-condensation product and rubber composition containing the same

Described herein is a process for preparing a hydroxyflavan compound which comprises reacting a polyhydric phenol compound represented by formula(2): ##STR1## wherein at least one of W, X, Y and Z is hydroxy; with a ketone in the presence of (i)an acid catalyst and (ii)water and/or a seed crystal, using an organic solvent which is insoluble in water, procuces the hydroxyflavan compounds in high yield and with high selectivity while maintaining high conversion of the polyhydric phenol.

Process for preparing hydroxyflavan compounds

The present invention relates to a method for producing a vulcanized rubber by compounding in a kneading step at a relatively high temperature, a rubber and a flavan compound of the formula (I) ##STR1## wherein R.sup.1, R.sup.2, R.sup.4 and R.sup.5 independently of one another represent a hydrogen or an aliphatic group having 1-6 6 carbon atoms, or R.sup.1 and R.sup.2 together with the carbon atoms to which they are attached and/or R.sup.4 and R.sup.5 together with the carbon atom to which they are attached form an alicyclic ring having 4-10 carbon atoms, R.sup.3 is a hydrogen or an aliphatic group having 1-6 carbon atoms, and X and Y independently of one another are hydrogen, hydroxy or an aliphatic group having 1-8 carbon atoms; also, a rubber composition containing a flavan compound according to the above formula together with a cobalt-containing compound and a methylene donor; the vulcanized rubber produced through the method or from the rubber composition exhibits excellent rubber properties such as, for example, increased hardness and processability essentially free from fuming problems.

Rubber composition containing a flavan compound and a method for

A rubber composition (1) which comprises:

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Takatsuki, Japan

Hironobu Iyama